Use SettingsLib Indexable

- Use SettingsLib Indexable
- Directly use resource id in getPreferenceScreenResId

Bug: 135053028
Test: roboletric
Change-Id: I05f493b55e8b6e2091301e9231ba5615215618e6

src/com/android/settings/homepage/TopLevelSettings.java

@@ -50,7 +50,7 @@ public class TopLevelSettings extends DashboardFragment implements
 
     @Override
     protected int getPreferenceScreenResId() {
-        return SEARCH_INDEX_DATA_PROVIDER.getXmlResourceId();
+        return R.xml.top_level_settings;
     }
 
     @Override